package python-cryptography 1.2.3-1 failed to install/upgrade: subprocess new pre-removal script returned error exit status 1

[Clodoaldo Rodrigues]

Whe I'm connecting to the system display these error

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: python-cryptography 1.2.3-1
ProcVersionSignature: Ubuntu 4.4.0-51.72-generic 4.4.30
Uname: Linux 4.4.0-51-generic i686
NonfreeKernelModules: nvidia
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: i386
Date: Wed Nov 30 23:55:28 2016
ErrorMessage: subprocess new pre-removal script returned error exit status 1
InstallationDate: Installed on 2015-10-22 (411 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release i386 (20150422)
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.1
 apt 1.2.15
SourcePackage: python-cryptography
Title: package python-cryptography 1.2.3-1 failed to install/upgrade: subprocess new pre-removal script returned error exit status 1
UpgradeStatus: Upgraded to xenial on 2016-05-02 (218 days ago)

[Nish Aravamudan (nacc)]

Hello and thank you for filing this bug report.

It seems like you must have some local configuration change, as the issue is:

Preparing to unpack .../python-cryptography_1.2.3-1ubuntu0.1_i386.deb ...
  File "/usr/bin/pyclean", line 63
    except (IOError, OSError), e:
                             ^
SyntaxError: invalid syntax
dpkg: warning: subprocess old pre-removal script returned error exit status 1
dpkg: trying script from the new package instead ...
  File "/usr/bin/pyclean", line 63
    except (IOError, OSError), e:
                             ^
SyntaxError: invalid syntax
dpkg: error processing archive /var/cache/apt/archives/python-cryptography_1.2.3-1ubuntu0.1_i386.deb (--unpack):
 subprocess new pre-removal script returned error exit status 1

which is not a syntax error in python2, but is in python3. Did you by any chance change your default python interpreter (/usr/bin/python) to python3 (not recommended or allowed by PEP).

Can you provide:

apt-cache policy python-minimal
python -V

outputs?

[Launchpad Janitor (janitor)]

[Expired for python-cryptography (Ubuntu) because there has been no activity for 60 days.]